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3.5mm Headphone To RJ9/RJ10/RJ22 Phone Adapter

Use your 3.5 mm headset with your phone through this 3.5mm to RJ9 adapter. Convert your standard smartphone headset to work with your office phone.
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  • PH35-RJ9a Front View
  • Smartphone Headset to Aastra Phone Adapter
  • 3.5mm OMTP male lead
  • 3.5mm vs 2.5mm guide


  • Convert 3.5mm Smartphone plug to single 4P4C RJ9/RJ10 handset plug.
  • Save money by buying a smartphone headset, or using your existing one with your Aastra phone's handset jack.
  • Reduce clutter with single headset.
  • Does not work with RJ11 jack, which is wider than your handset or headset jack (6 positions vs. 4). RJ11 jack is what is in the wall. RJ9, RJ10, RJ22 are what is on your phone handset or headset.
  • Works best with 4-pole (TRRS) headsets. Not compatible with Apple EarPods. 

This amazing adaptor converts the standard 3.5mm smartphone plug to an Aastra RJ9, RJ10, or RJ22 handset plug, allowing you to use your favorite smartphone headset with your Aastra office phone. The adapter outputs binaural sound for stereo headsets, meaning you will hear sound out of both ears. The adapter cable is approximately five inches long.

**Works best when paired with an amplifier**


Free returns, always!

We have a 30-day, no-questions-asked return policy for all of our products as well as a one-year, 100% Satisfaction guarantee; We’ll replace your Headset Buddy for free within the first 12 months.

For further information about Headset Buddy's Warranty and Shipping & Returns policies select the imbedded links

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*For optimal use, please plug into the headset jack on your phone. The handset jack usually causes audio distortion

This list is not all inclusive. Please look up the specifications on your specific phone to see if it has a RJ9, RJ10, or RJ22 headset jack. If the Headset Buddy doesn't work with a model on this list we will be happy to refund 100% of your purchase plus pay for return shipping.

Incompatible phones

Avaya 1100, 1200, 1600, 2000, 4600 and 9600 series

Cisco phones

Nortel 1140T and Visa 350

Most Polycom phones

Shortel IP 230

Uniden Dect2088, TRU9496

Western Electric 6250

Compatible Phones

Aastra/Packet8/8x8 480e, 480i, 53i, 55i, 57i, 57iCT, 6753i, 6755i, 6757i, 9112i, 9133i, 9143i, 9480i

Allworx 9212

AltiGen IP Phone 500, 510, 600, 705, 710, 720

Avaya 4500 Series IP

ESI 48-Key IP Feature Phone and 48-Key Digital Feature Phone

GE Model 2-9451


Lucent 8410D

Mitel IP 40XX, 41XX, 5000, 50XX, 5140, 52XX, 53XX, 5550

NEC Dterm Series E

Norstar T7316E, M3904

Nortel IP 1120E IP, 1140E IP, 1150E IP, 1230, i2002 and i2004

Nortel Meridian Norstar Northern Telecom

Panasonic Hybrid

Plantronics T10

Polycom VVX300

Possum Sero

Shoretel ShorePhone IP models


Splicecom PCS 520

Talkswitch IP Phone, TS-600


3COM 3102, 3103

Compatible Amplifiers:

Plantronics S-12, M22, A20, MX10, TSB, AP15

Please let us know if you find more incompatible or compatible phone models.

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